Projecting machine



I 1927. Apr! 12 E. E. LEHWESS PROJECTING MACHINE Filed Jan. 6, 1923 m m m m 3 EaouHmELEHI YESS a r w fip'ATTORA/EY.

WI TNESSES:

Patented Apr. 12, 1927.

UNITED STATES PATENT OFFICE.

PROJECTING MACHINE.

Application filed January 6, 1923. Serial No. 610,995.

This invention relates to feed mechanisms for projecting machines and more especially to that portion of the feed mechanism which produces an intermittent feed of a film strip to bring successive pictures of the film in register with an aperture in the film gate, where, by any suitable arrangement of objective with a. source of light, pictures are. projected upon a screen in the well known manner.

The mechanism is also suitable for the projection or display of glass slides conveyed by a belt or chain in sequence on a disc of glass -or other suitable material; where the movement of the pictures is intermittent and where the period of rest may be of short or long duration.

The particular embodiments of my invention are shown in theaccompanying drawings in which Figure 1 is an elevation of one form of construction. I

Figure 2 is a modified form of operating device partly in section that may be used to actuate the shaft 0, in Fig. 1.

Figure 3 is an elevation of. a further modified form and in particular shows the driving of the projector by a motor.

Figures 4 to 6 are details of construction of the arrangement of the form of escapement shown in Figure 3.

Referring to Fig. 1, there is mounted on shaft a an oscillating member 6 which .is or embodies an-armature of suitable form secured to the shaft a. A frame or support 1; and 11 adjacent the armature has bearings to support the shaft 0. and has a stop 6 adapted to engage a cooperating stop 1) associated with the armature so-that the extent of oscillation of the armature, and therefore the shaft a is definitely predetermined and positively limited. A coil 0 has a core of any usual form with the bars or extensions 27 and a forming poles which are energized by current passing through coil 0. These pole pieces t and 10 extend into proximity of opposite sides of the armature b, so that energizing the pole pieces creates a magnetic field and forces the oscillation of the armature b around its supportuntil the stop b engages the stationary stop I). Suchmagnetic actuation turns the shaft a against the resistance of the spring d, so that when the current from 1" is broken the spring (I; having been put in tension reacts to turn the shaft aback to its initial position of engagement by the pin 70 with the pawl on the spool member 7', and thereby oscillates the armature I) back to its initial position. This provides for an uninterrupted oscillation "of the shaft a a predetermined definite amount limited by the force imparted by the spring until the pin it passes over the pawl and catches it and with a positive limitation of stop '1). which prevents b from passing in either direction, and a forward drive of the film or picture always the same definite extent, in order that it may provide a drivin mechanism to assure positive feed of a. de nite section of film or definite individual slides or similar picture element. In Fig. 2 the driving mechanism may be replaced by the solenoid c in which is mounted a cylinder m of non-conducting material which guides a core n actuated by the solenoid 0 connected with a linko to a crank p which is'keyed or otherwise secured to the shaft a in Fig. 1.

Preferably at the end of shaft a, and in any event secured to it in a suitable position, is a disc or flange a which may carry a pin la adapted to engage a pawl 70 on a spool member f suitably fashioned with teeth g or the like, adapted to engage the perforations on a film e in order to drive the film in known manner, or having teeth or other engaging means to engage a band, chain or the like to transmit step-by-step motion for the purposes'of this pro ector. A gate i may have projections h to guide in known manner the movement and predetermine definite position of the film. The spool f being driven at one end has at the other end a stop 10 adapted to engage a pawl la having a fixed support adjacent'and mounted in a manner whereby the predetermined os cillation of the spool in the driving direction is held by the pawl 70 a; prevent the the armature may be given an eccentric position with respect to the shaft a so as to reduce the inertia of starting by helping the predetermined revolution. When the curmagnetic action with gravity, and in turn when the reverse movement of the armature begins gravit may help the spring, therefore assuring minimum size and strength of parts, smoothness and quickness of action. Thus the construction provides for the minimum strength of .current required for the driving mechanism, and this in turn reducing the strength of current at the contacts of make-and-break apparatus "minimizes Wear and prolongs the life, making the mechanism in practice more eflicient and economical. As this class of projector is intended for operating for long periods and automatic, it is of the greatest importance that the least possible attention and great durability of all parts determine superiority of the entire mechanism. VVithout attendants, the clockwork s, or other suitable automatic means may be disposed in the circuit 1- leading to the coil 0 or the solenoid a, so as to interrupt the current at predetermined periods or intervals.

The operation of the devices hereinbefore described is as follows:

When the circuit of the coil 0 or 0'. is closed by the clockwork or other suitable device the coil. 0 will be energized so that a magnetic field is produced between its poles t and w and the armature b will be oscillated through a predetermined fraction of a revolution. In the, case of the modified mechanism in Figure 2 the solenoid 0' is energized, when the core n will be raised so as to rock a shaft a, which shaft is the spool driving shaft shown in Figure 1. In this modified form the fractional rotation of shaft a is to the extent of the throw of the crank p actuated by the solenoid core or plunger 11, connec-tedby link 0 with the crank 79, and when the current is cut ofi the spring 9 pulls back the crank p to its initial position and pulls down the core to the bottom of the solenoid, thus putting it in a position to repeat the next rotation ste as soon as the circuit is again closed. 1e rocking movement of the shaft a, causes a partial movement of the spool f which feeds the film, band, chain or the like the distance of one picture through the gate. After the coils have been energized to produce the rocking movement of the shaft a as described the current to the coils will be interrupted, the spool will be held in its advanced position by the cooperation of k and A. and while the shaft a returns to its initial position (LlHQtO the ratchet connection is releasing from the spool, whereas the ratchet k on the other end of the spool holds the spool in its advanced position so that the film or the like remains stationary in the gate until the circuit is again closed by the clockwork and the armature or core actuate the shaft a again for the fractional rent is interrupted the armature b is returned to its original position by the sprin 03 whilst the core 'n is returned to its origina position by the spring 9.

The feeding mechanism may also be arranged as shown in Figures 3, 4" and 6,

which show a modified form ofstep by step, or periodic advance'of the pictures, by means -of a motor driven by an electric current.

The shaft a is provided with teeth 1 which gear with a toothed wheel 2 formed integrally with a spring casing 4 mounted on a shaft 3. Adjacent the toothed wheel 2 there is loosely mounted on the shaft 3 a disc 5 provided with a number of pins 6. Y To the inner surface of the disc is secured one end of a spring 7 of which the other end is con nected to the shaft 3. The shaft 1 is driven by a small motor 12? through gearing 13 which drives the shaft a and this in turn through the toothed, portion of the toothed wheel 2 drives the shaft 3. Rotatably mounted on the shaft 0 is-a sleeve a to which is secured a retarding disc 8 provided with a notch 10. This. retarding disc 8 normally engages with one or more of the pins 6 and thus prevents the rotation of the disc 5 so that when the shaft 3 is rotated the spring, 7 will be tensioned. The disc 8 is also provided with a pin 11 projecting.

the notch 10 the disc 5 is released and will be moved rapidly by the spring 7 and turn the disc 8. This movement of the disc 8 serves to advance the film or the like this being efi'ected by means of forks or projecting members 12 provided on the sleeve a After the members 12 have moved the film through the required distance they disengage therefrom. On the further rota-r tion of the shaft q, the pin 9 is caused to catch up the pin 11, which has been moved in advance thereof by reason of the rotation of the disc 8 by means of the disc 5, and will cause the disc 8 to bereleased from the pin 6 and lock the disc 5 against further movement so that the spring 7 will again be tensioned. The pin 9 remains in engagement with the pin 11 until the notch 10 is again brought opposite one of the pins 6. These operations are continued so that the pins 6 of the disc 5 will be brought into operation successively.

In Figure 3, 14 indicates the lens which projects the images directly or by reflection by means of suitable mirrors to a suitable screen or other surface on which the image is to be observed. V

In the modification shown in Figure 5 the members 12 are replaced by friction seg ments 13 which exert a slight pressure against the film e orthe like which bears against a spring mounted roller 14 or the like, thus providing for a driving engagement of the film by pressure between the segment 1.3 and roller 14 From the description of the relation of parts and their operation, it will thus be seen that in any of the forms, the'mecha nism guides a film or the like by feeding forward at a desired time interval readily predetermined, and that each step of the feed is quick and between feeds the film or the like is at rest and registers as predetermined with the gate, for the desired display. The mechanism is simple and particularly in the forms shown in Figures land 2, it provides the means whereby actuating current'need be used only for the short interval of forward drive, with no loss of current during the re; mainder of the time. The'limited motion of the moving parts of the mechanism involve practicall' no wear, and the ratchet mechanism is o the simplest form with accuracy and positive drive, and besides the certainty of operationthese parts as well as the rest of ,the mechanism can be made at small cost, with accuracy, and in all provide at a durable and serviceable mechanism fully meeting all the requirementsof such a projector step feed mechanism.

It will be understood that various modifications may be made without departing from the spirit of the invention. For example instead of using films, bands or the like post cards or small opaque objects may be arranged on polygonal rollers or the like which are adapted to be rotated intermit- 3 tently in the manner hereinbefore described.

.The apparatus described is particularly suitable for advertising purposes and may be adapted for use in conjunction with conditionally transparent mirrors on the back of which the object on the film or the. like is projected or reflected. In the case ofa transparent film an suitable illuminating means may be provided for projecting the images thereon on to the backof a conditionally transparent mirror. The circuit for the illuminating means may also be controlled by the clockwork so that whilst the film is being moved the mirror will act as an ordinary mirror whereas when the film is-stationary the light will cause it to be projected on to the back of the mirror so' that the image may be seen therein.

While various modifications may be made in detail and arrangement, and the 1nven 'tions may be variously combined, otherwise than as hereinbefore shown and described, what I claim and desire to secure by Letters Patent is: i

1. A feed mechanism for projecting apparatus wherein the feed of the film or other pictures are suitably arranged for intermittent projection, comprising an automatic" electric driving mechanism, means between the driving mechanism and the film strip or like picture mounting toefi'ect alternately a quick feed of the film or like a predetermined and always uniform extent, said the electric drive, means to switch on a momentary current actuating the mechanism a substantial part of a revolution against the resistance of the spring, means for breaking the current and allowing returnmotion by the spring energy to the initial or normal position.

2. A fecd mechanism for projecting apaneans including a spring cooperating with paratus, wherein the feed of the film, strlp .coil for rocking said shaft in one dlrection,

means for intermittently making-and-break mg sald circuit, and means between the actuatmg-sh'aft and film strip or the like includinga one-way driving connection and I controlling means to uniformly advance each image a predeterminedand always a fixed distance.

3. In' projecting apparatus feed mechamm for intermittent still projection, a feed mechanism comprising a film sprocket or the like, a'shaft and a one-way drive connection between sa d shaft and sprocket, electromagnetic means connectedwithsaid shaft to oscillate the same'in the driving direction a substantial part of but less than a whole revolution, a spring temporarily put in tension by the electrically operated means to return said shaft to its initial position and means for holding said sprocket or the like with its connected film always in a fixed uniformly advancedposition when the oneway drive mechanism is released.

4. (A feed mechanism for projecting apparatus adapted to provide intermittent motion and a stationary period for still projection, comprising film or picture drive con-- nections, a shaft to drive the same including a one-way clutch, electro-magnetic means to oscillate said shaft quickly in one directiona predetermined distance and fixed means to-uniformly limitthe successive motions, a clutch for holding said sprocket stationary for the still interval, and a clock controlling the current to the electro-magnetic means to control the still intervals and periodic feed.

\ or other picture supporting means is suitably arranged for successive movements, a rotating drive for the feed mechanism electrically actuated and a sto to arrest the rotation at a fixed point, a rive pin to rotate the feed mechanism a predetermined extent suflicient to completely displace always one image on the film strip or other picture support means, a reverse acting spring set intension by the'forward driving mechanism,

means for" cutting the current and inter-- connections to automatically return the feed mechanism to a predetermined point for initial starting of thedrive.

6. projecting apparatus wherein the feed of the film strip or other picture-supporting means is arranged for successive movement under automatic control, comprising electrically actuated means to uniformly feed the film or the like positively and always the same forward uniform distance,

means momentarily cutting in-and-out an ating the driving mechanism uniformly back always to a predetermined initial position. 4

electric current driving said electrically actuated means, and non-electrical means actu- I 

